The best speaker for a small room...at any price point.

Agree with the Raidho suggestion (or Borresen if you can swing the funds). Consider the D1 or possible even D2 if it's a dedicated room. Nice thing about Raidhos is they're designed to be placed wide apart and close to side walls (though they need 3+ feet from front wall). They're amazing speakers with a glorious tweeter. Smaller Vivids are also quite nice in a smaller room.
I moved from a large room with full range Peak Consults (and subs) to a smaller 13'x16' room. Both my Raidho D2 and Vivid 1.5 sound great in this room. Bass is solid and tight to 40Hz. On some music I miss the extended bass I was used to, but for most music it isn't an issue (either that, or I've adjusted). Room treatments and bass traps can be a great help if it's a dedicated room. 

Other possibilities: Though not at the same sound level as Raidhos and Vivids, the Larson speakers work up against the front wall and work well with room modes. I heard them at a dealer and was impressed. I'd also consider Kii standpoints--their DSP evens out the bass response and goes quite low. Haven't heard them but would like to...

Value: Fritz Carrera BE.

All-out: Gamut RS3i.

Imaging and if bass is  not huge to you, reference 3a dulcets, mm decapo

Do you like electrostatics? If so, consider either of the Janszen models. The controlled directivity minimizes wall and ceiling interactions, which is helpful in a small room. They sound great, too!  --very low distortion and maximum transparency.